1. Field of the Invention
The invention relates to a system for collecting samples of saliva for body fluid constituent analysis.
2. Description of the Related Art
Saliva testing has recently come to the forefront as a preferred option in body fluid constituent analysis. The collection procedure is non-invasive, and saliva has been found to be a very reliable carrier of analyte indicators. For instance, PKU tests on infants are now regularly done, drug abuse is tested in many circumstances, HIV testing may be relatively reliably performed with saliva, and levels of therapeutic drugs may be ascertained through saliva testing.
A recent advance in saliva collection and test preparation is disclosed in U.S. Pat. No. 5,103,836 to Goldstein et al. An absorbent pad which is impregnated with a salt of a hypertonic solution is inserted into the mouth and saliva is brushed off from the cavity walls. After having absorbed a sufficient amount of saliva, the pad is removed and stored in a vial for later testing. The test kit is suited for immunoglobulin collection and testing for immunological information in the body fluid. That prior art test provides enough saliva for only a single test, i.e. the saliva is not collected for general, multiple testing.
Another saliva collector is disclosed in U.S. Pat. No. 5,268,148 to Seymour. A portion of filter paper is exposed so that, when enough saliva is collected, the paper will provide an indication that the collected amount is adequate.
The method and apparatus described in U.S. Pat. No. 4,774,962 to Hebel et al. allows extracting saliva from the human body in that a sponge member is chewed for a certain amount of time and after saliva has been absorbed in the sponge member, it is centrifuged therefrom. The method may be acceptable for adult saliva collection. Such a free sponge, however, is essentially unsuitable for infant testing due to the danger of ingestion and it is also not acceptable in view of the proposed utilization thereof in HIV and hepatitis testing.
The prior art devices have in common that the collection of saliva sample is rather cumbersome, it exposes the medical worker to dangerous substances, and/or the amount of saliva thus collected is inadequate to perform various tests. Also, none of the prior art devices provide a convenient method and kit for collecting a large amount of saliva for body fluid constituent analysis. Finally, saliva collection from very small infants, for instance for PKU testing, is quite difficult and virtually always accompanied by forcing the infant's mouth open during the procedure.